Was the sure grip unit for a 2.45 gear set? If so this is the problem. There are lots of these out there for sale right now. If you install the ring gear on your original open carrier will it set up?

The 96 ring and pinion should not be an issue. I installed a 3.55 from a Jeep in my Duster with no problem at all. The spline count did change on the carrier on later ones but the gears were not affected.